Timing chain guides and head/valve work are anticipated maintenance items, typically recommended around 150K miles, with head rebuilds estimated near $5K and leaky valves a known S38 weakness.
Timing chain and valve service
BMW E28 M5 · mechanical
Timing chain guides and head/valve work are anticipated maintenance items, typically recommended around 150K miles, with head rebuilds estimated near $5K and leaky valves a known S38 weakness.